Potential role of ultra-sensitive estradiol assays in estimating the risk of breast cancer and fractures.

Radioimmunoassays (RIA) for the measurement of estradiol are sufficiently sensitive to assess the reproductive status of pre-menopausal women but lack sufficient sensitivity for low concentrations found in post-menopausal women. Bioassays have been used in the past to measure low estrogen levels but are impractical for handling high volumes of tests, particularly routine and non-research specimens. In this study, we compared results for estradiol using several different methods including bioassay, RIA, and two tandem mass spectrometry methods. At the lower tertile of estradiol measurements by RIA, the overall excellent correlation with results obtained by tandem mass spectrometry (i.e. r=0.83) was lost (i.e. r=0.29). In addition, results were much lower with bioassay and mass spectrometry than with RIA suggesting that RIA measures undesired noise or estrogen metabolites. The mass spectrometry methods correlate best with isotopic kinetic methods when assessing aromatase inhibition. On this basis, we conclude that mass spectrometry assays are the best option for measurement of low estradiol concentrations. With such assays, greater discrimination should be achievable when using estradiol levels as a predictor of the risks for breast cancer and for fractures.

Treatment of advanced pancreatic cancer with opioid growth factor: phase I.

Opioid growth factor (OGF) is an endogenous pentapeptide that inhibits growth of human pancreatic cancer cells in culture, as well as xenografts in nude mice. To establish the maximum tolerated dose (MTD), and determine safety and toxicity of OGF, a phase I trial was performed in patients with advanced unresectable pancreatic cancer. Patients with unresectable pancreatic adenocarcinoma were treated with escalating doses of OGF for 30 min i.v. to determine the MTD. The s.c. route of administration also was evaluated. Once the MTD was established, a group of patients was treated chronically, and monitored for safety and toxicity. Hypotension was the dose-limiting toxicity, resulting in a MTD of 250 microg/kg i.v. Due to limited solubility of OGF in small volumes, a maximum dose of 50 microg/kg twice daily was determined by the s.c. route of administration. No adverse events were reported for oxygen saturation, cardiac rhythm, laboratory values or neurological status in either the acute or chronic parts of the study with the i.v. or s.c. routes. During the chronic i.v. phase, two subjects had resolution of liver metastases and one showed regression of the pancreatic tumor. Mean survival from the time of diagnosis was 8.7 months (range 2-23 months) in the i.v. group and 9.5 months (range 1-18 months) in the s.c. group. We conclude that OGF can be safely administered to patients with advanced pancreatic cancer. Further studies are needed to determine the efficacy of OGF alone or in combination with present modes of therapy for the treatment of pancreatic cancer.

A comparison of multiple urine markers for interstitial cystitis.

PURPOSE: We measured several urine markers in 24-hour specimens from patients with interstitial cystitis and healthy controls. For each marker we determined whether the urine level was significantly different in interstitial cystitis and control cases, and whether the marker level correlated with the symptom score. MATERIALS AND METHODS: Study participants included 36 female patients with interstitial cystitis and 36 age matched female volunteers. Multiple urine aliquots were obtained to measure the various markers. RESULTS: Certain markers were significantly increased in interstitial cystitis, including anti-proliferative factor, epidermal growth factor, insulin-like growth factor (IGF) binding protein-3 and interleukin (IL)-6. Markers significantly decreased in interstitial cystitis were heparin-binding epidermal growth factor-like growth factor, cyclic guanosine monophosphate and methylhistamine. Other markers were not significantly different in the interstitial cystitis and control groups, including total glycosaminoglycans, epitectin, hyaluronic acid, IL-8, IL-1 and nitrates plus nitrites. IGF-1 was undetectable in 24-hour urine samples but spot voided samples from the same interstitial cystitis population had IGF-1 levels similar to previously reported levels. The only significant association of marker with symptom score was a positive correlation of IL-6 with nocturia. For all markers the conclusions were the same whether the marker was normalized to creatinine or to 24 hours. CONCLUSIONS: This study confirmed several previously reported urine alterations in interstitial cystitis, including increased anti-proliferative factor, epidermal growth factor, IGF binding protein-3 and IL-6, and decreased heparin-binding epidermal growth factor-like growth factor and cyclic guanosine monophosphate. Of all markers studied anti-proliferative factor had the least overlap in the interstitial cystitis and control groups, and so it is the most likely candidate to become a diagnostic test.